On Thu, May 30, 2013 at 3:23 PM, David Roberson <dlrober...@aol.com> wrote:
> There seems to be a serious hangup over why a heat generating device needs > some form of heating input to sustain itself. The skeptics can not seem to > get their arms around this issue so I will make another short attempt to > explain why this is important. > > To achieve a high value of COP the ECAT operates within a region that is > unstable. This translates into a situation where the device if given the > chance will attempt to increase its internal energy until it melts or > ceases to operate due to other damage. Control of the device is obtained > by adding external heat via the power resistors allowing the core to heat > up toward a critical point of no return. > > Just prior to that critical temperature the extra heating is rapidly > halted. The effect of this heating collapse is to force the device core > heating to change direction and begin cooling off. > I do get the basic idea. The problem is I don't see how to make it work in the latest experiments. The switching would have to be on a pretty slow time scale, because of thermal mass. It would take on the order of minutes for an appreciable change in the internal temperature to result from shutting down the resistors, as is consistent with the rather slow change in temperature in the March experiment. But in the December experiment, there is no switching on this time scale. The power is measured on the lines to the ecat, and they claim the power is constant as recorded by the PCE830 on a 1 second time scale. Also they say that the power output is almost constant on the same time scale. So, I fail to see how that kind of a scheme could work there. The input in that experiment is 360 W applied to the resistors, and that is allegedly enough to trigger the reaction. The total output power is about 2 kW, so that would be 1.6 kW generated by the reactor *inside* the cylinder. If 360 W from outside is enough to trigger the reaction, how can 1.6 kW not be enough to keep it going? I picture someone holding a butane lighter to glowing coals, and expecting them to extinguish when he takes the lighter away. Now, you might discount the December run, but then you'd impugn Levi's integrity, and since he was clearly in charge in March, that makes the whole thing kind of dodgy. But even in the March run, things don't add up. They claim it takes about 800 W to the reactor from the resistors to trigger the reaction. From the geometry, only a fraction of that power will actually be absorbed by the reactor itself. (The rest will be absorbed by the ceramic and the end caps.) The average output from the reactor is also about 800 W, but this is generated inside the reactor, so again, it makes no sense that the reaction would extinguish when you turn the external power off. Furthermore, in all cases, it seems implausible that the output would be that stable without any feedback from the reactor output. Even if the sort of control you talk about were possible, it would require the exact duty cycle to keep the temperature from drifting up or down. And even if Rossi found the right duty cycle, it seems unlikely it would stay the same for 4 days at those temperatures. People are always excusing the absence of progress by suggesting the reaction is so hard to control, but from both these experiments, it appears to be rock stable. That would be the case if the heating were all resistive. The behavior looks nothing like you would expect a new reaction sensitive to temperature would look. > Positive feedback can work in either direction; that is, the temperature > can be either increasing or decreasing and the trick is to make it go in > the desired direction. > > Are you saying positive can be negative. What's the trick to making it decrease when 1/5 the power makes it increase? The closer to the critical point that Rossi is able to switch directions, > the longer the temperature waveform will linger near that point before > heading downward. This is a delicate balance and most likely the reason > Rossi has such a difficult fight on his hands to keep control. High COP, > such as 6, is about all that can be safely maintained. > Sorry, but it sounds like nonsensical speculation to me. > > The explanation above is based upon a spice model that I have developed > and run many times. > To model the behavior, you need to propose a reaction rate (power out from the reactor) as a function of temperature, and the temperature dependence of the reactor on the power produced by the reactor and the external input. What functional dependence do you use for these? I can't think of any that would work. Again, if 360 W from the outside gets it going, why can't 1.6 kW on the inside keep it going? In the old ecats, with a resistor inside the reactor, one could possibly conceive of a method if the resistor produced higher temperature concentrated a single point, and the reaction were diffuse throughout the core. That would be like cold coals, where you need to keep a flame on them until they ignite. But in the hot cat, once it's producing more heat than the resistors, its heat will be more localized and at a higher temperature than you can get from the external resistors.
